@angels live,
I think it comes down to this:
What to you believe the relationship is between fetus and mother?
If you believe the unborn child is no more independent, in any way, of the mother than a non-essential organ then you can make a case that the government should not dictate what the mother can and cannot do with the fetus.
You might even think that the government should not tell anyone what they can or cannot do with an essential organ: abort their heart and commit suicide, but abortion never equals suicide and so the issue is irrelevant.
If on the other hand, you believe that a fetus is a human life independent of the mother and that women, for good or bad, are stewards, not the possessors of the unborn, then you need to ask yourself how you want government to regulate the taking of individual lives.
You might think the government should not control one person's taking the life of another, in which case you won't have much trouble with abortion no matter what you think about the nature of a fetus.
My difficulty with the pro-choice position is the degree to which its supporters seem to be able to twist and distort their own morality to legitimize abortion.
Certainly some people honestly believe that a fetus is essentially nothing more than an appendix. I find this a disturbing belief, but if sincere, it leads to logical support of legal abortion.
I'm afraid that I just don't believe that most pro-choice advocates hold this belief.
Oh, a lot of them will say they do, but only a few will actually mean it.
Instead most of them will apply the "Who am I to tell someone else..." principle, and they will take great comfort in this moral cover. It allows them to avoid a starkly honest examination of themselves.
If you accept the premise that you have no right to pass judgment on the decisions and actions of others, then it's easy to avoid taking any sort of moral stand.
All well and good, except the vast majority of people who subscribe to this creed are quite happy to pass judgment on people who engage in behaviors that don't fit within their moral (read political) construct.
We have no right to pass judgment on anyone who kills a fetus, but most certainly do when it comes to someone who thinks the press built up Donovan McNab because he is black, that illegal aliens should not receive the benefits accorded to legal citizens, or that we should bomb Iran rather than allowing them to obtain nukes.